package com.manong.utils;

import com.manong.entity.User;
import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.stereotype.Component;

import java.util.Date;
import java.util.HashMap;
import java.util.Map;
/*
* 封装令牌
* */
@Data
@ConfigurationProperties(prefix = "jwt")
@Component
public class JwtUtils {
    //密钥    
    private String secret;
    // 过期时间 毫秒    
    private Long expiration;

    private String generateToken(Map<String, Object> claims) {
        Date expirationDate = new Date(System.currentTimeMillis() + expiration);
        return Jwts.builder().setClaims(claims).setExpiration(expirationDate).signWith(SignatureAlgorithm.HS512,
                secret).compact();
    }
        public Claims getClaimsFromToken(String token){
            Claims claims;
            try {
                claims = Jwts.parser().setSigningKey(secret).parseClaimsJws(token).getBody();
            } catch (Exception e) {
                claims = null;
            }
            return claims;
        }
        /**     * 生成令牌     *     * @param userDetails 用户     * @return 令牌     */
        public String generateToken(UserDetails userDetails) {
        Map<String, Object> claims = new HashMap<>(2);
        claims.put(Claims.SUBJECT, userDetails.getUsername());
        claims.put(Claims.ISSUED_AT, new Date());
        return generateToken(claims);
        }
    /**     * 从令牌中获取用户名     *     * @param token 令牌     * @return 用户名
     *
     */

    public String getUsernameFromToken(String token) {
        String username;
        try {
            Claims claims = getClaimsFromToken(token);
            username = claims.getSubject();
        } catch (Exception e) {
        username = null;
        }
        return username;
    }


    public Boolean isTokenExpired(String token) {
        Claims claims = getClaimsFromToken(token);
        Date expiration = claims.getExpiration();
        return expiration.before(new Date());
    }
     public String refreshToken(String token) {
        String refreshedToken;
        try {
            Claims claims = getClaimsFromToken(token);
            claims.put(Claims.ISSUED_AT, new Date());
            refreshedToken = generateToken(claims);
        } catch (Exception e) {
        refreshedToken = null;
        }
        return refreshedToken;
    }
     public Boolean validateToken(String token, UserDetails userDetails) {
        User user = (User) userDetails;
        String username = getUsernameFromToken(token);
        return (username.equals(user.getUsername()) && !isTokenExpired(token));
         }}


